Mig Welding Car Body

  1. 1fifer1 Member

    Messages:
    24
    Location:
    Uk East Riding
    Hi I want to weld a couple of patches onto my car wheel arch, now disconnect the battery I know but is there any thing else electrical that needs attention?
    regards
     
  2. Craig-SM

    Craig-SM Member

    Messages:
    910
    Location:
    Leeds
    Make sure there is nothing flammable in the surrounding area you’re welding. Something I should have done a better search for.
    If you have an air compressor then use an air line to cool the panel whilst welding to prevent distortion and you’ll be doing a series of spot welds to reduce heat build up.
     
    stuvy likes this.
  3. 1fifer1 Member

    Messages:
    24
    Location:
    Uk East Riding
    noted thank you !
     
  4. the snooper

    the snooper getting older by the day

    Messages:
    20,577
    Location:
    Hull UK
    If you want it to last let a piece in, don't weld it over the top, Ive never removed the battery either
     
    stuvy likes this.
  5. 1fifer1 Member

    Messages:
    24
    Location:
    Uk East Riding
    Right not even disconnect the terminals ? I all ways thought it was a must do, thanks any how !
     
  6. the snooper

    the snooper getting older by the day

    Messages:
    20,577
    Location:
    Hull UK
    Nope never disconnected anything, unless I was welding a new battery tray in :D some people remove the connections religiously I never have
     
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  7. 1fifer1 Member

    Messages:
    24
    Location:
    Uk East Riding
    That's good to know feel a lot more confident now thanks
     
  8. Al Strachan

    Al Strachan Not Funny

    Messages:
    256
    Location:
    Aberdeenshire
    You do need to pay a little attention to where your earth goes. if you are welding a wheel arch make sure you earth to the bodywork, not a wheel stud or suspension component. The earth path could potentially be routed via a wheel bearing (bad) or earthing via a tiny sensor cable or small earth strap (very bad).
     
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  9. 1fifer1 Member

    Messages:
    24
    Location:
    Uk East Riding
    so a decent earth strap from the engine to the body should be good enough ?
     
    Mr Roo likes this.
  10. James1979 Member

    Messages:
    899
    Location:
    Orkney
    Some cars it's bad to remove the battery. Totally screws with the brain.

    I leave it on but always use a surge protector across the terminals
     
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  11. James1979 Member

    Messages:
    899
    Location:
    Orkney
    Just grind up a bit of body to bare metal and earth of that
     
    stuvy likes this.
  12. Mr Roo

    Mr Roo Member

    Messages:
    366
    Location:
    Edinburgh
    i’d probably weld a bolt or a piece of steel onto a non-descript part of the car, relatively close to where you’re welding.

    have had earth clamps jump off nearly every existing component when trying to weld cars, so now I just add my own earth point.
     
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  13. metalmelt Member

    Messages:
    381
    Location:
    UK
    Wheel arches are nearly all double skinned panels so open it up carefully ans check what's inside the cavity before even thinking of welding, many modern cars come with some form of cavity protection and while many may be a form of galvanising many used a rubber/plastic based coating; and a previous owner may have used caity wax or even oil.
     
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  14. 1fifer1 Member

    Messages:
    24
    Location:
    Uk East Riding
    I'm so glad to have started this thread, a wealth of knowledge and experience coming forward, many thanks
     
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  15. Nick DV

    Nick DV "You must unlearn what you have learned."

    Messages:
    576
    Location:
    Southampton
    That's exactly why this forum is such a good one :thumbup: Lots of helpful and clever people (not me though ;)) here.
     
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  16. hillman Member

    Messages:
    60
    cheshire
    When I've struggled to get the earth to clamp on, eg on a sill' I just put an old pair of vice grips on the flange or edge and put the earth clamp on them.
    I've got an old pair where the spring has broken just for that purpose.
     
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